add header guard

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@40165 a592a061-630c-0410-9148-cb99ea01b6c8

diff --git a/src/tex2lyx/Preamble.h b/src/tex2lyx/Preamble.h
index 7eebf26c29803306ba1aaaeac3a6a4cbf1f8d549..f8149077a3db52fd469f9aa2fc4d9c3899c5442a 100644 (file)
--- a/src/tex2lyx/Preamble.h
+++ b/src/tex2lyx/Preamble.h
@@ -11,6 +11,9 @@
 
 // {[(
 
+#ifndef LYX_PREAMBLE_H
+#define LYX_PREAMBLE_H
+
 #include "Author.h"
 
 #include <iosfwd>
@@ -167,3 +170,5 @@ extern Preamble preamble;
 
 
 } // namespace lyx
+
+#endif